Allowing My Girlfriend To Have Sex With Another Guy

Me and my girlfriend have been together for 5 years now and are madly in love with each other. However we have always looked for ways to make our sex lives even better.
She is 5’7, slim with big DD boobs and is genuinely so hot. She attracts a lot of male attention if we’re out. I like that guys want her and although she pretends not to like the attention, I can tell she loves it.
I tend to work a lot so she goes out with her college friends a lot. She always comes home with stories of guys trying to hook up with her and flirting with her because she always felt guilty. If she was single, I can guarantee she would have no issues finding guys to have sex with.
One day we were talking about people we find attractive and if we had a list of people who we’d love to Hook up with. In all honesty I really didn’t care about hooking up with other girls, I just loved the idea of her booking up with other guys.
At first I thought she would make a list of celebs that she found hot but she added names of people from our town. I couldn’t believe it, she was a little reluctant to say it but we always remain open. They were guys that were definitely into her and that she knew, I personally had never spoken to them but they seemed like the sort of type that liked to sleep around. Sporty, College jock types that were in terrific shape. As attractive as they were, they would be lucky to get near my girlfriend because of how ridiculously hot she is.
Maybe a week went by and the conversation never came back up and she was heading out with her friends again while I was at home working on my laptop. She looked stunning as per usual with a revealing tiny black dress on. I was thinking about her list all week and was really turned on by the idea. So I told her as she was leaving, “feel free to tick a name or two off that list of yours if you want”. She was shocked but almost as if she was pretending to be. She kept asking if o was sure and if it would be ok. I reassured her that it was and I would sleep in the spare room for the night too. She kissed me so passionately before she left and was delighted I agreed to it.
So the night dragged on and I kept an eager eye on my phone for messages from her but there was nothing about a guy, just snaps of her and her friends. So I put my phone down and was about to turn in when my phone lights up with a Snapchat from her. I opened it and it was a pic of her outside in what looked like an alley. She looked a little drunk. There was an arm around her. The caption said “is it ok if I bring home someone?”.
I replied with “ok yes of course”.
She then sent back another pic of the same angle but of his hand down her dress and on her boobs. The caption read “I feel so slutty, is this ok?”.
I was immediately turned on by this and knew when she got back it would be some crazy sex going on. I reassured her that it was and told her the bedroom was free. I went to the spare room and turned the lights off. about 10 minutes passed and I was wondering where she was. I got back a pic of her with her bra in her hand. So I just left her on read. Within 5 minutes I heard a commotion at the door and a scramble for keys. I heard the door barge open and heavy panting and groaning. I could see the entire bedroom from the spare room as it was right beside it. But they couldn’t see me. They were all over each other and kissing and stripping down. He was a big guy and a little older and he was definitely experienced at this. They got to the bed and she lay down as he stood over her. She pulled off her dress and took her dress off revealing her perfect white skinned body. Her nipples were hard and I could see her biting her lip so I knew she was very horny. He stood up and pulled down his trousers and I was shocked at how big his dick was. I have to admit I am big but this guy was huge. She sat up immediately and began to play with it. She kissed it and then sucked it. She was slowly sucking it when he grabbed her head and legit began facefucking her. I’d never seen this side of her, she took the whole dick in her throat. He was saying things like “I bet your boyfriend doesn’t hit the back of your throat”. This went on for a while until he couldn’t be any more erect. He picked her up like a doll and put her on all fours and without any hesitation began fucking her from behind. It was a crazy sight to watch my girlfriend get fucked soooo hard but I loved it and she clearly did too. I’d never heard Moans like it. I was so turned on that I didn’t even notice there was no condom. I was just hoping they would be careful. They then switched to missionary where he was kissing her neck and deeply fucking her. He began getting faster and I could see her in absolute heaven.
This went on for 10 minutes of consistent pounding when he began to groan way more aggressively as he slowly decreased speed and just came to a complete stop. He was still inside her but not moving. Just kissing her, he eventually pulled out a semi hard dick which was dripping in cum. As he pulled out, a stream of white liquid poured from her gaping vagina. He lay beside her for a bit as they kissed a little more and teased each other. After a while he got up and started putting clothes back on. She just lay there, completely wore out as he left.
I went into her and immediately noticed how red cheeked she was. She looked so satisfied. I don’t think she was at all bothered that he didn’t pull out. It was almost as if, this wasn’t the first time.............